# Senior Test Engineer - HIL - Company: [Onenergy]() - Location: Houston, Texas, United States - Team: Research & Development - Posted: September 11, 2026 ## Job description ON.energy is building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software, ON.energy develops projects worldwide that set new benchmarks for resilience. ### Role Summary The HIL Test Engineer develops and operates hardware-in-the-loop and real-time simulation capability for ON.energy storage and power conversion products. The role covers real-time model development, integration of controllers and firmware with the simulation environment, execution of structured test campaigns, and the reporting that supports design reviews and product release. This is a hands-on laboratory and integration role, working closely with the controls, firmware, modeling, and product engineering teams. ### Key Responsibilities * Develop and maintain real-time models of plant, grid, and equipment behavior for use in controller testing. * Configure and operate the HIL environment, including real-time simulator, I/O interfaces, signal conditioning, and data acquisition. * Integrate product controllers, control software, and firmware builds with the simulation environment, and maintain those configurations under version control. * Integrate supplier-provided equipment models and develop equivalent models where required. * Plan and execute functional, performance, fault, boundary-condition, and regression test campaigns against defined acceptance criteria. * Verify control performance across normal operation, disturbances, abnormal conditions, and recovery. * Compare test results against offline simulation studies and laboratory measurements, and resolve discrepancies. * Develop scripts and tooling to automate test execution, data processing, and reporting. * Investigate failures with controls and firmware engineers, support root-cause analysis, and re-test to closure. * Prepare test reports documenting method, configuration, results, limitations, and recommendations. * Maintain laboratory safety, equipment, configuration records, and documentation. ### Key Requirements * Four or more years in HIL testing, real-time simulation, controls validation, or laboratory testing of grid-connected power electronics. * Bachelor's degree or higher in electrical engineering, power systems, controls engineering, or a related discipline. * Direct experience on at least one real-time simulation platform, such as RTDS/RSCAD, Typhoon HIL, or OPAL-RT. * Working capability with offline simulation tools such as MATLAB/Simulink and PSCAD, and an understanding of what has to change when a model is made to run in real time. * Grounding in inverter controls, energy storage systems, and power system dynamics. * Python, or a comparable language, used in earnest for test automation and data analysis. * Test plans, procedures, and acceptance criteria you have authored yourself, and the analytical rigor to stand behind the results. * Familiarity with SCADA systems and industrial communication protocols such as Modbus, DNP3, CAN, and IEC 61850. * Comfort on the bench with power supplies, oscilloscopes, transducers, and data acquisition hardware. * The ability to present technical findings credibly to engineering audiences and clearly to field and commissioning personnel. Preferred Experience * Experience with grid-forming and grid-following inverter control. * Experience with uninterruptible power supply systems, microgrids, or facilities serving critical load. * Familiarity with ISO or utility interconnection requirements, model quality testing, or third-party product certification. * Continuous-integration pipelines driving automated test suites, with version control applied to models as rigorously as to code. * Prior collaboration with national laboratories or university test centers. --- **For US-based roles - What you’ll get:** * Competitive salary + annual performance-based bonus eligibility * Medical, dental, and vision insurance * 401(k) with company match * Paid time off and company holidays **For Mexico-based roles - What you’ll get:** * Competitive salary + annual performance bonus eligibility * Christmas Bonus (Aguinaldo): 30 days * Major medical expenses and life insurance * Paid time off and holidays (per local policy) **For all roles:** * Professional development and growth opportunities * Opportunity to grow with a mission-driven team shaping the future of clean energy * Equal Opportunity: ON.energy is committed to equal employment opportunity and to maintaining a work environment free of harassment, discrimination, or retaliation. * Accommodations: If you need an accommodation during the application process, email [recruitment@onenergystorage.com](mailto:recruitment@onenergystorage.com) * Benefits vary by role and location and are subject to change. **Agency Notice:** ON.energy does not accept unsolicited resumes from staffing agencies, search firms, or third-party recruiters. Resumes submitted without a fully executed Master Services Agreement (MSA) and a written request from an authorized member of our Talent Acquisition team will be considered the property of ON.energy. No placement fees or compensation will be paid for unsolicited candidate submissions. ## Apply [Apply on Onenergy]() Canonical job page: